This public page describes the research of the 2008-2009 L-3 Senior Clinic project team on a project titled, "Phased array AOA-enabled localization and tracking in buildings".
L-3 Communications Systems West has funded a U. of U. Department of Electrical and Computer Engineering Senior Clinic on the topic of angle-of-arrival (AOA)-based localization in wireless sensor networks. This project follows up on a successful 2007-2008 L-3 sponsored clinic on AOA-based indoor localization.
This clinic team will design and implement a phased-array antenna to measure angle-of-arrival (AOA) information for the purpose of high accuracy 3-D localization in buildings. Compared to the relative-RSS method for AOA measurement developed in the 2007-2008 clinic, the phased array antenna is both more accurate and more difficult to implement. The phased array will be implemented using GNU radio software and the universal software radio peripheral (USRP) hardware boards. Work has been done to enable the reception of 802.15.4 (Zigbee) signals in the USRP/GNU radio platform . The clinic team will extend this work to receive Zigbee signals simultaneously and synchronously on multiple receive antennas. Then, they will program the receiver software to calculate the measured received power vs. angle. The students will conduct measurements in indoor areas to model the reliability and accuracy of angle-of-arrival measurements in building environments. They will also refine the AOA-based localization algorithm developed in the current-year clinic project, to be able to locate and track node positions as they move through a building. Algorithms will operate in real time so that a laptop can display current locations to a user.
This clinic is advancing the state of the art in wireless sensor networks by improving our ability to estimate 3-D sensor location. Estimation of sensor location is a key first step in environmental monitoring applications, in which a large number of sensors are deployed across a large area, both for in-building and outdoor monitoring applications. In order to make use of the sensed data, we must know where the sensors are. Accurate 3-D localization is also critical in warehouse and factory floors, in which extremely low-power radio tags placed on boxes, parts, and equipment allows them to be located at all times.
This clinic team is developing angle-of-arrival (AoA) measurement technologies using wireless devices, and improving distributed location estimation algorithms. The team is investigating two different angle-of-arrival measurement methods, using software radio to implement a phased antenna array, and using multiple commercial wireless sensors with directional antennas. The team is also investigating and implementing new distributed algorithms which use the AOA measurements to improve location estimates.
A restricted workspace is available for team members.
Some helpful links can be found below: